Abstract: Waveguide membrane on Si basement was fabricated by So-Gel method with a special kind of organic Si as raw material. After a serial of tests including thickness test, optical test and XPS test, it was concluded that this membrane was thick enough and has good quality. Since Sol-Gel method always causes chap and split, a method how to deal with it was discussed. Finally, how to fabricate an arrayed waveguide grating with the membrane was also introduced.